Honda-SOHC
SOHC.co.uk Forums => CB350/400 => Topic started by: taysidedragon on May 07, 2019, 05:58:59 PM
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I'm having a bit of a problem with my front brake pivot arm. There's too much play on the pivot. I changed it for a spare one which was better but still has a small amount of play.
Is any amount of play acceptable?
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Do you mean play between pin andarm (radial) or along the pin (axial)?
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Do you mean play between pin andarm (radial) or along the pin (axial)?
If I hold the caliper I can move it up and down slightly because of the play at the pivot. Someone told me there shouldn't be any play at all. The pivot pin would have to be a tight sliding fit for no play at all.
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... I can move my K2’s caliper up/down about 3mm due radial wear. Has always been like this. The 400F however has zero play, and the SS50 about 1mm. Will be interesting to learn of any published allowable tolerances.
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... I can move my K2’s caliper up/down about 3mm due radial wear. Has always been like this. The 400F however has zero play, and the SS50 about 1mm. Will be interesting to learn of any published allowable tolerances.
I seem to remember reading on here some years back that Honda issued some washers/shimming to address the issue on the earlier 750K's, as they had a different design bracket/pin than the 350/400/500/550 and later 750's. With the latest design, if there seems to be too much up/down movement on the pin you can try new "O" rings top and bottom of the calliper arm, or very slightly elongate the holes in the top part of the pin bracket, allowing it to be mounted fractionally lower to take up the wear, but don't move it down too much or the arm may bind causing caliper drag. Also, that is only good for taking up wear at the top and bottom of the arm, if the actual bore in the arm where the pin passes through is worn, find a GOOD engineer (such as Trigger) who can machine it out and bush it to standard size again.
Sent from my X6pro using Tapatalk
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It's the bore in the arm for the pin that seems to have worn. I've ordered a 'new' arm.
Hopefully it will be fine.
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It's the bore in the arm for the pin that seems to have worn. I've ordered a 'new' arm.
Hopefully it will be fine.
You should see if you can get a new pin as well, that way it's all new parts together!
Sent from my X6pro using Tapatalk
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It's the bore in the arm for the pin that seems to have worn. I've ordered a 'new' arm.
Hopefully it will be fine.
You should see if you can get a new pin as well, that way it's all new parts together!
Sent from my X6pro using Tapatalk
DSS sell new pins, but my steel pin shows no wear. All the wear is in the aluminium arm, allegedly! ☺
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Drill and tap housing for a grease nipple and lube it regularly.
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Hi Tayside,
6 yrs ago (!) I started this thread - found it now / may shed some light on your issue?
Simon.
http://www.sohc.co.uk/index.php/topic,4934.0.html
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There is a bush in the alloy arm that can be replaced to match the pin.
Another trick is loosen off the two top bolts and squeeze it down with a G clamp then, tighten the two top bolts.
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Hi Tayside,
6 yrs ago (!) I started this thread - found it now / may shed some light on your issue?
Simon.
http://www.sohc.co.uk/index.php/topic,4934.0.html
Thanks Simon, that thread is really useful. If necessary, I'll try the shim solution.
If that fails it'll have to be a new bush in the arm.
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You know i had forgotten about that bulletin! Old age or Guiness , not sure which!
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...for the first time in a year or so I had 2 pints of Guinness for lunch. Dear god I’d forgotten how good it is...
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Tayside... you cost me a couple of hours work today!
Anyways, was changing the K2’s pads over to semi-sintered, and took a harder look at the caliper ‘nod’... which in truth was now concerning. The ‘nod’ was radial, and all due the pin slop in the top / bottom carrier.
Engineers look away now, but I fixed it by using lengths of feeler gauge cut to match the pin circumference and inserted into the carrier. To take the split pin I simply used a punch once the holes were lined up...
FYI the feeler gauge thicknesses needed were 9 & 10 thous; implying the carrier holes are about 20 thou oversized. (The pin is new). (Odd jobs shim-washers went back in)
There is no play in the caliper now, and I have bought myself a bit of time whilst I either source a new carrier or quality engineering to fabricate an insert.
Cheers,
Simon
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I suppose that'll work for a while. I don't think I'll be going down that road, but I've seen worse things done on a bike! 😉
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I fitted the new brake arm today and there is no play now, either radial or axial.
I'm a happy bunny now. 8)